Wireless LAN
Uses, Benefits & Disadvantages

style="font-family: Verdana; margin-left: 40px; text-align: justify;">WirelessLAN technology, while replete with the conveniences andadvantages described above, has its share of downfalls. For a givennetworking situation, wireless LANs may not be desirable for a numberof reasons. Most of these have to do with the inherent limitations ofthe technology.

• Security: Wireless LAN transceivers aredesigned to servecomputers throughout a structure with uninterrupted service using radiofrequencies. Because of space and cost, the antennas typically presenton wireless networking cards in the end computers are generallyrelatively poor. In order to properly receive signals using suchlimited antennas throughout even a modest area, the wireless LANtransceiver utilizes a fairly considerable amount of power. What thismeans is that not only can the wireless packets be intercepted by anearby adversary's poorly-equipped computer, but more importantly, auser willing to spend a small amount of money on a good quality antennacan pick up packets at a remarkable distance; perhaps hundreds of timesthe radius as the typical user. In fact, there are even computer usersdedicated to locating and sometimes even hacking into wirelessnetworks, known as wardrivers.On a wired network, any adversary would first have to overcome thephysical limitation of tapping into the actual wires, but this is notan issue with wireless packets. To combat this consideration, wirelessnetworks users usually choose to utilize various encryptiontechnologies available such as Wi-Fi Protected Access(WPA). Some of the more older encryption methods, such as WEP are knownto have weaknesses that a dedicated adversary can compromise. (Seemain article: Wireless security.)0906-0901

• Range: The typical range of a common802.11g network withstandard equipment is on the order of tens of meters. While sufficientfor a typical home, it will be insufficient in a larger structure. Toobtain additional range, repeatersor additional access points will have to be purchased. Costs for theseitems can add up quickly. Other technologies are in the developmentphase, however, which feature increased range, hoping to render thisdisadvantage irrelevant. (See WiMAX)

• Reliability: Like any radio frequencytransmission, wireless networking signals are subject to a wide varietyof interference,as well as complex propagation effects (such as multipath,or especially in this case Rician fading) that arebeyond the control of the network administrator. In the case of typicalnetworks, modulation is achieved bycomplicated forms of phase-shift keying(PSK) or quadrature amplitudemodulation (QAM), making interference and propagation effectsall the more disturbing. As a result, important network resources suchas servers are rarelyconnected wirelessly.

• Speed: The speed on most wirelessnetworks (typically 1-108Mbit/s) is reasonably slow compared to the slowest common wirednetworks (100 Mbit/s up to several Gbit/s). There are also performanceissues caused by TCP and itsbuilt-in congestion avoidance.For most users, however, this observation is irrelevant since the speedbottleneck is not in the wireless routing but rather in the outsidenetwork connectivity itself. For example, the maximum ADSLthroughput (usually 8 Mbit/s or less) offered by telecommunicationscompanies to general-purpose customers is already far slower than theslowest wireless network to which it is typically connected. That is tosay, in most environments, a wireless network running at its slowestspeed is still faster than the internet connection serving it in thefirst place. However, in specialized environments, the throughput of awired network might be necessary. Newer standards such as 802.11n areaddressing this limitation and will support peak throughputs in therange of 100-200 Mbit/s.